IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 12 at lib/refcount.c:28 refcount_warn_saturate+0x135/0x140 lib/refcount.c:28 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.7.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events do_enable_set Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x12d/0x187 lib/dump_stack.c:118 panic+0x22a/0x4e3 kernel/panic.c:221 __warn.cold.10+0x25/0x2a kernel/panic.c:582 report_bug+0x1b0/0x270 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:175 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:refcount_warn_saturate+0x135/0x140 lib/refcount.c:28 Code: 20 df fd 0f 0b e9 51 ff ff ff 48 89 df e8 a3 74 41 fe e9 1f ff ff ff 48 c7 c7 20 34 0e 88 c6 05 e2 4f 98 06 01 e8 93 20 df fd <0f> 0b e9 2a ff ff ff 0f 1f 40 00 55 be 04 00 00 00 48 89 e5 41 57 RSP: 0018:ffffc90000d2fbf0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88808fdcf018 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8adde120 RBP: ffffc90000d2fc00 R08: ffffed1015d466a9 R09: ffffed1015d466a9 R10: ffff8880aea33547 R11: ffffed1015d466a8 R12: 0000000000000003 R13: ffff888097c14c00 R14: 0000000000000000 R15: ffffc90000d2fe48 refcount_sub_and_test include/linux/refcount.h:274 [inline] refcount_dec_and_test include/linux/refcount.h:294 [inline] kref_put include/linux/kref.h:64 [inline] l2cap_chan_put+0x175/0x1d0 net/bluetooth/l2cap_core.c:502 do_enable_set+0x48a/0x8b0 net/bluetooth/6lowpan.c:1075 process_one_work+0x893/0x1690 kernel/workqueue.c:2268 worker_thread+0x85/0xb60 kernel/workqueue.c:2414 kthread+0x354/0x420 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Kernel Offset: disabled Rebooting in 86400 seconds..